2010 年 76 巻 772 号 p. 3274-3281
A new framework of identifying the crack position in a structural member in terms of numerical simulation is presented. In this methodology, the extended finite element method (XFEM) is used to analyze the vibration problem of the structure which has a straight crack on its surface. To identify the position of a crack, the gradient of a evaluation function is used, and that function is calculated by using the eigen frequencies of the structural members both with real crack position and with estimated crack position. In the numerical examples, two dimensional cantilever beam members are used, and the identification of crack position has conducted. In some cases the evaluation function has several residual points, or has very flat distribution around the real crack tip. To identify the crack position certainly, setting up several starting points becomes reasonable approach.